Process of making a tobacco smoke filter from a split film of cellulose acetate

ABSTRACT

A cellulose acetate film is subjected to stretch operations which are carried out under conditions such that highly oriented molecular chains are created therein and then to splitting whereby a netlike configuration composed of numerous stem fibers and branch fibers linking adjacent stem fibers is obtained. A tobacco smoke filter is formed from the split acetate film after additional treatments including crimping.

United States Patent Tokitomo et a1.

[15] 3,675,541 51 July 11,1972

1541 PROCESS OF MAKING A TOBACCO SMOKE FILTER FROM A SPLIT FILM OFCELLULOSE ACETATE [72] Inventors: Soichi Tokitomo, Tokyo; MasakazuHonda; Fumio Nakayama, both of Toyama; Keisiro Ueno, Otake, all of Japan[73] Assignees: Mitsubishi Rayon Company Limited; Mitsubishi AcetateCompany Limited, Tokyo, Japan 22 Filed: June 2,1970

21 Appl.No.: 42,625

Related US. Application Data [63] Continuation-impart of Ser. No.687,351, Dec. 1,

1967, abandoned.

[30] Foreign Application Priority Data Dec. 13, 1966 Japan ..41/8l636[52] US. Cl ..93/1 C, 131/261 A, 156/83, 156/167, 156/180, 264/147,264/288, 264/DIG. 47, 264/DIG. 48

[51] Int. Cl ..B29d 7/24, B32b 31/08, D04h 3/16 [58] Field of Search..l31/266-269, 10 R, 131/261 R; 28/1 CF, 1 CS; 93/1 C; 156/83, 180,

167, 229, 172; 161/109, DIG. 6; 264/147, DIG. 47,

DIG. 48, 288

Primary Examiner-Robert F. Burnett Assistant Examiner-Robert A. DawsonAttorney-Robert E. Burns and Emmanuel .1. Lobato ABSTRACT A celluloseacetate film is subjected to stretch operations which are carried outunder conditions such that highly oriented molecular chains are createdtherein and then to splitting whereby a netlike Configuration composedof numerous stem fibers and branch fibers linking adjacent stern fibersis obtained. A tobacco smoke filter is formed from the split acetatefilm after additional treatments including crimpmg.

7 Claims, 7 Drawing figures CELLU LOSE FLAKE OF ACETATE FILM FORM 1N6SPLIT FILM ORIMPED S PLlT FILM FILTER MASS 1N CYLlNDRICAL F c IGARETT FlLT ER ROD PA'TE'N'TEDJUL I 1 I972 SHEET 10F 2 CELLU LOSE FLAKE OFACETATE FILM FORMING SPLIT FILM ORIMPED SPLIT FILM FILTER MASS INCYLINDRICAL FORM C IGARE TT FILT ER ROD PROCESS OF MAKING A TOBACCOSMOKE FILTER FROM A SPLIT FILM OF CELLULOSE ACETATE The presentapplication is a continuation-in-part of our copending application, Ser.No. 687,35l, filed on Dec. 1, 1967, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a tobacco smokefilter composed of cellulose acetate in the form of split film. Moreparticularly, the present invention relates to a tobacco smoke filtercomposed of split cellulose acetate film having a netlike configurationof numerous stern fibers and branch fibers which link adjacent sternfibers and a process for producing the same.

Generally, conventional cigarette filters are composed of a mass offibers, such as rayon or acetate fiber, polyolefin fiber, etc. In thepresent cigarette filters, acetate fiber is preferably used due to itsexcellent features.

A typical method for manufacturing conventional cigarette filterscomprises opening a tow of crimped fibrous material for the filter;adding some suitable bonding agent or plasticizer to the openedmaterial; gathering the prepared material to form a cylindrical mass andmaking the cylindrical mass of material compact; next, wrapping a paperaround the cylindrical mass of material and .then cutting the wrappedcylindrical mass of material intorods for use as filters for cigarettes.

Another method for manufacturing a cigarette filter wherein the additionof the bonding agent to the opened material is omitted has also beenproposed.

However, in the first case, the selection of a suitable bonding agent orplasticizer is necessary to obtain cigarette filters of uniform quality;further, the process for manufacturing the filter is complex and theexpense of installation and maintenance of manufacturing machines ishigh. In the second case, a filter plug having an uneven cut face issometimes produced because the fibers contained in the gatheredcylindrical mass are not bonded to each other; further, it is inevitablethat the cut waste of the fiber is mixed into the recovered tobaccowhich is one of the raw materials of a lower grade cigarette.

SUMMARY OF THE INVENTION Another object of the present invention is theprovision ofa' filter which provides excellent filtration of tobaccosmoke and which is composed of a netlike configuration of fibers madefrom a split film of cellulose acetate which has the property of beingreadily splittable and fibrillated.

Another object of the present invention is to provide a method formanufacturing a tobacco smoke filter whereby the defects of conventionalmanufacturing methods are eliminated.

It has been discovered that a highly cfi'ective filter for tobacco smokeis comprised of a bundled mass of split cellulose acetate film having aplurality of stem fibers and branch fibers connected to each other in anetlike configuration and provided with crimp, said stem fibers havingan average diameter of not more than 39.5 microns, the unit length ofsaid stem fibers as defined by adjacent branch fibers being below 20mm.

and the total fineness of said cylindrical mass being below 100,000denier.

According to the invention, thecellulose acetate film used The tobaccosmoke filter of the present invention may be used in any tobaccoproduct, such as cigarettes, cigars or in cigarette or cigar holders orin a tobacco pipe stem; further, the filters of the present inventionmay be formed to fit into a refillable filter holder for use in anysmoking article.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a flow sheet of anembodiment of the method for manufacturing a tobacco smoke filteraccording to the invention.

. FIG. 2 is an explanatory drawing of the configuration of fibers of thesplit film of cellulose acetate of the invention.

FIG. 3 is another explanatory drawing of the configuration of the splitacetate film according to the present invention.

FIG. 4 is a side view of a cylindrical mass of the netlike configurationof fibers according to the present invention.

FIG. 5 is a perspective view illustrating one method of forming thefilter shown in FIG. 4.

FIG. 6 is a perspective view illustratinganother method of forming thefilter shown in FIG. 4.

FIG. 7 is a schematic diagram for stretching and splitting acetate filmaccording to the present invention DESCRIPTION OF THE INVENTIONReferring to FIG. 1, the tobacco smoke filter of the invention ismanufactured by a process which involves splitting a film of celluloseacetate by a conventional mechanical method whereby the celluloseacetate film is converted into a split film having a netlikeconfiguration formed as a result of the splitting up motion of thesplitting machine. Next, the split film having a netlike configurationis provided with crimps by a crimping machine; thecrimped film isgathered, to form a cylindrically shaped filter mass, and then wrapped,with a paper. Thereafter, the wrappedcylindrical mass is cuttransversely into filter. rods. When it is required to bond the fibersof thefilm at their contact-point, a bonding treatment -is aporientationof the molecular chainalong the length of the film ous stretching takesplace, the total stretch ratio in the second stage of the stretchingoperation is in the range of about 1.4 to 4.0 with respect to an acetatefiber of non-stretched condition.

plied to the fiber film before it is gathered.

However, it has been found that the usual acetate film cannot be usedfor the present purpose because of its poor splitability andfibrillatability. By splitability is meant the spontaneous enlargementof a slit or cut out portion, in the working direction of the mechanicalslitting or cutting-means,.which occurs in some films when a portion ofa film is cut or slit by certain mechanical action, such as a knifeunder tension. Generally films whichare splitable'also have the propertyof undergoing fibrillation, i.e. the ability to form fibrils along thesplitting direction.

To clarifythe causeof the poor splitability and fibrillatability of theusual acetate film, many experimental tests were carried out and it wasdiscovered that it is difficult to effect splitting of acetate film in alengthwise direction and to cause fibrillation of the film, and it hasbeen concluded that this difficulty is due mainly'to the difficulty ofcreating a high orientation of the molecular chain along the length ofthe film even when a stretching operation is applied. Generally to splitfilm and create fibrils, when a film is partly cut along the lengththereof, it is necessary thatthe cut line expand readily along itslength rather than laterally in order that splitting of the film takeplace along its length. However, it has been found that in the case ofacetate film, the dimensions of the cut out portions of the film createdinitially by the mechanical slitting or cutting action do not changemuch over a long period of time without the application of additionalmechanical splitting action nor are fibrils generally created. Further,the out line of ordinary acetate film expands along the length and alsolaterally. While the present invention is not limited by theoreticalconsiderations, the main reason for poor splitability of the acetatefilm is believed to be due to poor orientation of the molecular chain.

In order to attain the purpose of the present invention it is desirableto produce an acetate film having high orientation of 'the molecularchain, Le. a cellulose acetate which may be readily split to form anetlike configuration and 'Aecordingg to; the present: I preferable touse'ja diacetate film having degree of acetylation of 48 6t0pericent andmore; preferably 52-58percent. ,A'n acetate film having thedesiredsplitability is prepared'by v "a ,two-ltage fpro'cess', lntheffirstistag'e, the film is stretched lfalongitsilehgthat astretchr'atio betweenlland 1.6. In the second,stageofthejstretchingprocess, the acetate film is spon- I taneously stretched alongitsilength in an aqueousfsolution containing lJ-Bperc'ent' phenol at atemperature maintained in 1 a range from.20 to 100C preferably in arangefrom 50 to 7 v C. while positively-stretching the film; so that thetotal stretching ratio-(positive stretch'frat io and spontaneous stretchM ratio)tis'betwee'n and 4.0.lThefilrn' is'then washed in an al-' kalinebath to removethe phenol residue and dried.

invention, 'it has been found I .The first's'tretching operationmayt'belcarried out funder dry v e 'ieonditions-iat a'temperaturehigher' than 0 C. However, it

1 has beenfound to be advantageous to carry out'this operation inaliquid,containingaswelling agent.i Any Swelling agents t which do notdissolve the diacetate film;canbe usedrParticu: larly,a rij aqueoussolution containing 7 0 8 0percent methanol TorethanoLa-liquidcontaining SOpercent benzene and'20per--' cent alcohol, "or aliquid'containingnitrobenzene 9 0perce'nt and alcohol '1 Opel-cent ispreferably used The temperature vof solution inwhichlthe firststretchingoperation iscarried .outlis preferably maintained betweenroomtemperature and sboursoct,

, lthasbeenjfound thatthe'acetate film prepared as just] described hasexcellentproperties ofsplitabilityaind of creat- T: ing fibriIs andthereby is readily converted to a film having a nettlike'confi gurationas ShOWllzin FIG; 3; An acetate film Q I 'mizwi la and linkingthe'stem'fibersya plurality oftbranchfibers lb.

hesivematerial r'nay be addedfiothe' split film aftertherabove treated'by atwo-stage stretching operation according to the 1 presentinventionis readilyfibrillatedq'lhe cut out portions v aretpro videdwith a certain numberbf fibrils andthe'shapes t f and dimensions ofthese portions' ten d to change even when a t [weak mechanical'splittingactionis applied] 7 1 j I film having a thickness'between 0.01 and 0.04mm; is preferably. used to attain the purposes-of the present'inven-'tion. .l f r l The';,present tobacco'smoke filter comprising aplurality of split fibers of:celluloseiacetatelhaving a netlikeconfiguration tration ofthe'tobacco smoke. Some additional'substancesfor,

film;

,A: cell uloseacetate film for the'present invention maybe 1 "producedby extruding a solution ofacetate flakes containing theabove-mentionedadditives through a slit orifice. However, i 1 asal'readymentioned, such film is notreadilysplit and there- "rar it is preferabIeto stretch their film produced by this t method in order toallow'fibrillation of the film to' take place e t Many methods forsplitting film are well'knowmas disclosed in US Pat. ,Nos;3,253,072,3,'302,50l, etc.; however, a splitting-machine provided withaplurality of revolving blades a Y is preferable for'splitting thepresent film. lt i s also preferable btained with increasinggfinenesssof the split-up has excellent properties with regard tothetaste, smelland fil-.

. example' a delust'eringagenti such astitanium dioxide orzinc t foxide, plasticizer 'such as triacetylene, 'colorin'g agent; absor-vb'ent such.asYactivecarbdn,additional substances tof'improve 'thetasteor smell viii-the tobacco such as sorbitan monolaurate', f prop'y le'njeglycol stearate, may be added to thefilm before ltihe split tin'g;upoperation; additives which-do not disturb the l [splitting up.v 'of' thefilm and also which are not injurious [to health'and arenot dangeroussubstances may be added to the t f splitting action.;S incea pertinenthardnessand characteiiof e V f filtration is required for a tobaccosmokefilter, theytotal;

' x a t ing' the finenessiof textile fibers,gthat is'thedeniersyste'm,is

the averagelden ier of the stem fibers la must be -n'ot more thanpreferably below. 20.0 mm to prevent separation of individual f stemfibers from the'cylindric'almass of the split'filmfi 3-.

In the-process ,-of .the pres ent;invention.-' a conventional 1 systemmaybe applied. l urthe'r, when'itis'desired tojmakeia t .rnore compactfilter rod; a bondinggagentsuch asa'solution of 1 l developed a bonding,'gent inia liquid conditionisfthen Q ways, for-example; withfreference.t EIQ Sahd 6,ia fter form; 'ing a sheetZof the split fibers having thenetlike configuration-I ple, three sheets 2a, 2b and 2c having'thenetlike configuration ,make the cylindrical-mass *in adjacentsternfibers produced when the filmis split, I -v the netlike configuration mamas a plurality of stem fibers t FIG. 3 which "alsolillustra'tes'jthenetlik econfigurat'iori of the 7 split cellulose acetate film fot' theinvention'shows, jnx addition whichar'epresent in thesplit rum.-According to the invention, f

l5 denier; preferably denienandthe unitlengthotf the stem fibers ladefined by twojadj'acent bran'ch c fibers "lb', :isfl.

crimping method utilizing thest'uffingbox systemaorlgearing resin,cellulose derivative,-glue, casein, or other plastic orad mentionedcrimping operation. Irr-this case; it is "preferable'to T spread outithesplit byfmeans of, aispreajding machine; 7 therebythefilrn sheet o t";netlike configuration,comprisingafplurality of stem fibers 'linked'bybranch. fibersgistclearlysprayed on the film sheet and the film'isdried; I v i The filter of heinven'tion'mayfbe produced in"a;numb,er;

shown in FlG. 2 or 3, thesheetIZ ofthesplit fibers" is gathered f by atrumpet 4, thereby. the cylindrical mass of splitfibers pro- Y videdwith thecorrespondin gtthickness of the cigarette filter" canbeobtainedv t. i f

' Thereafter, thecylindrical mass 3, illustrated also in ElGi-4,

maybe cut transversely into individual filter rods as desired: in

FIG."6,a plurality of .crimped sheets of split fibers, for'zexamillustrated in FIGS. 2 and 3, are-superimposedon ea'chother together toform a'cylind rical mass 3. The numberrof films to v must bedecided bythe massof the" sh' p bc j M a j v L 1 It has been foundthattthetthinrier the diacetate film used, Y the :finer are the numerousstem fibersand branch fibers link-v" )nthe other hand, theaveragefineness the abovem'enfi tioned stem fiberscanb'e, madecoarseriby .a plying rough thickness of thefilter must be chosen inaccordance withthe'; 5 averagefineness of the stemlfibers. 'lfhefollowing table'sho'ws the pertinentconditionsrelative to the averagefinonessofthe stem fibers and the total thickness ofthe tobacco smokefilter which have resulted from our discoveries.

Totalthickness of the smoke filter in deniers Average fineness of tCalculated diameter I A 'p-(D) deniers(F) v mood-100,000 170,000-100,000

applied. Further, to determine the dimension of the fineness of 1 thestem ,fibers, the calculated diameter of the stem fibeitf'is obtained bythe followingformula';

m run' 'mn where,

D represents the calculated diameter of a stem fiber,

p represents the specific gravity of the film (p of diacetate film is1.32). In this calculation, the lateral cross section of the stem fiberis considered as a true circle.

For example, when using a diacetate film having a thickness of 20microns, a tobacco smoke filter tip, having total thickness of 55,000denier and average fineness of the stem fibers of 4.0 denier wasproduced. The characteristic feature of this filter was pertinent forthe purpose; that is, when the tip length was 17 mm., the weight of thetip was 158 mg., aspiration resistance 57 mm., the absorption quantitiesof tar, nicotine, phenolic agent were 34percent, 28percent, 63percent,respectively when measured by an ultraviolet absorption spectrometer,the hardness of the filter tip was l2percent when measured with aprecision micrometer of the dead weight type manufactured by the TestingMachine Co., type TMT.

As mentioned above, there are several embodiments of the process formanufacturing the tobacco smoke filter according to the presentinvention which are simpler than the process of the conventionalmanufacturing method of the cigarette filter. Thus, in the process ofthe present invention, the spinning process for manufacturing tow,comprising numerous filaments, which requires expensive equipment andthe maintenance cost of which is high, can be avoided. Further, it ispossible to produce the tobacco smoke filter of the invention by acontinuous process in a highly economical manner, as shown by the flowsheet of FIG. 1.

Further, according to the process of the present invention, it ispossible to provide the tobacco smoke filter with sufficient compactnessand hardness for practical use without treatment with a bonding agent.Consequently, the manufacturing cost of the tobacco smoke filter may besubstantially reduced by the process of the invention.

The following examples further illustrate the best mode currentlycontemplated for carrying out the present invention, but these examplesare not to be construed as limiting the scope of the invention in anymanner.

EXAMPLE 1 Referring to F l0. 6, a non-stretched diacetate film 5 was fedto a stretch device by a pair of feed rollers 60, 6b and a guide roller7. The stretch device comprises two pairs of rollers 80, 8b and 9a, 9b.The film 5 was stretched in an aqueous methanol solution 10 by thisdevice at a stretch ratio of 1.4. Next, the stretched film was squeezedby a pair of squeezing rollers 10a, 10b so that the methanol solutionwas squeezed from the film, then the film was washed in a water bath soas to remove the methanol completely from the film. The film was furtherfed to a next bath containing an aqueous solution of phenol and providedwith a second stretch means comprising two pairs of rollers 18a, 18b and19a, 19b, after passing over guide rollers 16 and 17. While beingcarried through this bath, the film spontaneously stretched while thestretch means stretched the film in the phenol aqueous solution at astretch ratio of 2.5 with regard to the original length of the film. Thethus-obtained stretched film was washed by passing through an alkalinewashing bath and a hot water washing bath 30. In the above-mentionedoperation, guide rollers 21, 22, 26a, 26b and 27 were used for guidingthe film to be carried to the following treatments, respectively. Afterwashing the film, water and phenol attached to the film are removed bypassing through a drying chamber 32 maintained at a temperature morethan 185 C, which is higher than the boiling point of phenol. Thusprepared diacetate film 34 had an excellent splitability property. Thefilm 34 was fed to a splitting device 36 disposed between two pairs ofrollers a, 35b and 37a, 37b so that a split film 38 having a desiredconfiguration was produced. The device 36 is a roller covered bynumerous pins. The split film 38 had a net-like configuration comprisinga plurality of stem fibers la provided with a plurality of fibrils and aplurality of branch fibers 1b linking the stern fibers 1a, further aplurality of fibrils 1c as shown in F IG. 3.

The average denier of the stem fibers was 8 denier (calculated diameteris 29.1 t) and the length of the stem fibers was around 10 mm. Afteradding an oiling agent to the fiber sheet, fifteen oiled sheets weresuperimposed on each other and the piled fiber sheets were provided withcrimps by the conventional stuffing type crimping machine. The averagenumber of crimps was 16 per inch of films. The steps of spreading outthe film, adding a bonding agent to the fiber sheets, gathering thecrimped fiber sheets, wrapping of paper around the cylindrical mass offiber sheet of net-like configuration, cutting the wrapped cylindricalmass of stem and branch fibers into tobacco smoke filter rods are allcarried out continuously by a cigarette filter rod manufacturingmachine.

In the above-mentioned process, the conditions for producing thestretched diacetate film 31 were as follows:

( l) Diacetate film:

degree of acetylation 57% width of film 15 cm. weight per l in. lengthof film 6.0 g. (2) Conditions of the first stretching stage:

swelling agent aqueous solution of 70% methanol temperature of theswelling bath 23C stretch ratio 1.4 treating time 5 sec.

(3) Conditions of the second stretching stage:

liquid contained in the bath aqueous solution of 2% phenol temperatureof the bath 70C. stretch ratio (spontaneous 2.5 to the original lengthand positive stretching) 5 sec. treating time (4) Washing conditions:

alkaline washing bath soda ash l g./l. wash ing agent of alkyl ethertype 50Cl cc./l. aqueous solution temperature of the washing bath 50C.hot water (5) Drying conditions:

hot air treating time 5 min.

A solution composed mainly of an acetone solution of secondary celluloseacetate containing 1 percent weight of titanium dioxide on the basis ofthe weight of cellulose acetate was prepared, and the cellulose acetatefilm was formed by a conventional film forming machine. The thickness ofthe produced film was 20 micron. Next, a continuous tape of 2 cm. widthwas manufactured by cutting the thus-produced cel* lulose acetate filmand then the split film was produced by applying the same stretching andsplitting operation as that of Example 1.

When the tape treated by the splitting machine was spread out, anet-like configuration of the fiber sheet, as shown in FIG. 3, wasobtained. The average fineness of the stem fiber was 7 denier and thesplit length of the film was around 10 mm. After oiling the fiber sheet,fifteen of the oiled sheets were combined and piled on each other, nextthe piled fiber sheets were provided with crimps by the conventionalstuffing type crimping machine. The average number of crimps was 15 perinch of films. Next, the same preparations as that of Example l wereapplied and a tobacco filter having excellent properties was produced.

EXAMPLE 3 The solution described in Example 2 was used to prepare thediacetate film for this example. A diacetate film having thickness of 20micron was formed by a conventional film forming machine and then thefilm was cut into a plurality of tapes of 35 cm.width, next each tapewas subjected to the same stretching operation, except that the totalstretch ratio was 4.0. Thereby the average fineness of the stern fibersof the net-like configuration made from the tape was denier and theaverage split length of the film was'around 10 mm. Next,

- the sheets of split fibers were provided with crimps by theconventional stuffing box type crimping machine. The average number ofcrimps of the sheetwas 18 per inch. And the crimped sheet was suppliedto the rod manufacturing machine I and the cigarette filters wereproduced in the same way explained in Example 1, without addition of theplasticizer. The above-mentioned processes were' carried'out bycontinuous operation without any difficulties. Further, thethus-produced tobacco smoke filter had excellent properties whenmeasured by the same method as described in Example l, for example,

the quantity of the nicotine absorption was 27 percent and the ing fromthe spirit and scope of the invention.

What we claim as new and desire to secure by Letters 5 Patent is:

1. Process for manufacturing a filter for tobacco smoke 1 comprising:

split fibers having a netlike configuration comprising a f plurality ofstem fibers and a plurality of branch fibers linking said stem fiberswith eachother so that the calculated average. diameter of said stemfibers is not more than 39.5 microns and the unit length of, said stemfibers.

defined by adjacent branch fibers is below about mm. 2. Processaccording to claim 1 ,in which said split film is then crimped, formedinto a cylindrically shaped mass, wrapped with paper and cuttransversely into a length suitable for use as a cigarette filter rod. V

3. Process according to claim] in which the'firs t stage of saidstretching is carried out in an aqueous solution containing aswellingagent. 7 1 g 4. Process for manufacturing a filter for tobacco smokeaccording to claim 1, in which a plurality of said split films aresuperimposed on each other and said plurality of superim posed splitfilms are crimped and formed into a cylindrical mass.

5. Process for manufacturing a filter for tobacco smoke according toclaim 1, in which a bonding agent is added to said split film and thesplit film is crimped and formed into a cylindrically shaped mass.

6. Process for manufacturing a filterfor tobacco smoke according toclaim 1, in which an absorbent is added to said split film and then saidsplit film is crimped and formed into a cylindrically shaped mass. v 7.Process for-manufacturing a filter for tobacco smoke ac-v cording toclaim 1, in which an additional substance to improve the taste or smellof tobacco is added to said split film and then said split film'iscrimped and formed into a cylindrically shaped mass. I

2. Process according to claim 1 in which said split film is thencrimped, formed into a cylindrically shaped mass, wrapped with paper andcut transversely into a length suitable for use as a cigarette filterrod.
 3. Process according to claim 1 in which the first stage of saidstretching is carried out in an aqueous solution containing a swellingagent.
 4. Process for manufacturing a filter for tobacco smoke accordingto claim 1, in which a plurality of said split films are superimposed oneach other and said plurality of superimposed split films are crimpedand formed into a cylindrical mass.
 5. Process for manufacturing afilter for tobacco smoke according to claim 1, in which a bonding agentis added to said split film and the split film is crimped and formedinto a cylindrically shaped mass.
 6. Process for manufacturing a filterfor tobacco smoke according to claim 1, in which an absorbent is addedto said split film and then said split film is crimped and formed into acylindrically shaped mass.
 7. Process for manufacturing a filter fortobacco smoke according to claim 1, in which an additional substance toimprove the taste or smell of tobacco is added to said split film andthen said split film is crimped and formed into a cylindrically shapedmass.